Also build the test code first, so tests can reside in source tree as
well as the test tree.
Finally, build local Sqlite with -fpic to give consistent linkage when
using either built-in or system sqlite.
Move sqlite source to a separate location, and build with
an intermediate library target. This permits us to set compile options
easier, including an important one, NDEBUG, which improves performance.
Sqlite 3.8.0.2 also includes an updated query planner which may improve
some queries, to be tested.
